AD 96-22572

[Federal Register Volume 61, Number 173 (Thursday, September 5, 1996)] [Proposed Rules] [Pages 46742-46743] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 96-22572]

======================================================================== Proposed Rules Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. ========================================================================

Federal Register / Vol. 61, No. 173 / Thursday, September 5, 1996 / Proposed Rules

[[Page 46742]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-SW-03-AD]

Airworthiness Directives; Bell Helicopter Textron, Inc.-- Manufactured Restricted Category Model HH-1K, TH-1F, TH-1L, UH-1A, UH- 1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Bell Helicopter Textron, Inc. (BHTI)--manufactured restricted category Model HH-1K, TH-1F, TH-1L, UH- 1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters. This proposal would require a one-time inspection of the tail rotor slider (slider) to verify that it was manufactured with the correct outside diameter. This proposal is prompted by a United States (U.S.) Army Safety of Flight message that reports that some sliders may have been improperly manufactured with an undersized wall thickness by U.S. Army vendors. The actions specified by the proposed AD are intended to prevent fatigue failure of the slider, which could cause loss of tail rotor control and subsequent loss of control of the helicopter.

DATES: Comments must be received by November 4, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Assistant Chief Counsel, Attention: Rules Docket No. 96-SW-03-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Mr. Uday Garadi, Aerospace Engineer, Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 2601 Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222-5157, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket No. 96-SW-03-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Office of the Assistant Chief Counsel, Attention: Rules Docket No. 96-SW-03-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Discussion

This document proposes the adoption of a new AD that is applicable to BHTI-manufactured restricted category Model HH-1K, TH-1F, TH-1L, UH- 1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters, which would require, within 5 hours time-in-service after the effective date of this AD, a one-time inspection of the slider, P/N 204-010-720-3 or P/N 204-010-720-003, to verify that it has a correct outside diameter dimension, and was therefore manufactured with the correct wall thickness. The U.S. Army reports that some sliders may have been manufactured by U.S. Army vendors with a 30 percent undersized wall thickness. The reduced wall thickness will reduce the fatigue strength of the slider. This condition, if not corrected, could result in fatigue failure of the slider, which could cause loss of tail rotor control and subsequent loss of control of the helicopter. Since an unsafe condition has been identified that is likely to exist or develop on other BHTI-manufactured restricted category Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH- 1P helicopters of the same type design, the proposed AD would require, within 5 hours time-in-service after the effective date of this AD, a one-time inspection of the slider using a calibrated caliper or micrometer to verify that it has a correct minimum outside diameter dimension. If the outside diameter is less than 1.300 inches, removal and replacement with a slider that has an outside diameter of 1.300 inches or greater is required. The FAA estimates that 80 helicopters of U.S. registry would be affected by this proposed AD, and that it would take 0.5 work hours per helicopter to accomplish the proposed inspection. The average labor rate is $60 per work hour. Replacement of the slider requires 8 hours, and required parts would cost approximately $72 per helicopter. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $46,560 if replacement of the slider is required in all of the fleet. The regulations proposed herein would not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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For the reasons discussed above, I certify that this proposed regulation (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

California Department of Forestry; Erickson Air Crane Co.; Garlick Helicopters; Hawkins and Powers Aviation, Inc.; International Helicopters, Inc.; Smith Helicopters; Southwest Florida Aviation; West Coast Fabrications; Western International Aviation, Inc.; Williams Helicopter Technology, Inc.; and UNC Helicopters: Docket No. 96-SW-03-AD.

Applicability: Bell Helicopter Textron, Inc.-manufactured Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H UH-1L, and UH-1P helicopters, certificated in the restricted category.

Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (b) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD.

Compliance: Required within 5 hours time-in-service after the effective date of this AD, unless accomplished previously. To prevent fatigue failure of the tail rotor slider (slider), which could cause loss of tail rotor control and subsequent loss of control of the helicopter, accomplish the following: (a) Using a calibrated caliper or micrometer, measure the outside diameter of the splined shaft of the slider, part number (P/ N) 204-010-720-3 or P/N 204-010-720-003, at two points that are 90 degrees apart on the outside circumference of the splined shaft, one-half to one inch from either end of the slider. If the outside diameter of the slider is less than 1.300 inches, remove the slider and replace it, prior to further flight, with a slider that has an outside diameter of 1.300 inches or greater. (b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Rotorcraft Certification Office, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Certification Office.

Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Certification Office.

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished. Issued in Fort Worth, Texas, on August 27, 1996. Daniel P. Salvano, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 96-22572 Filed 9-4-96; 8:45 am] BILLING CODE 4910-13-M